Re: [PATCH] objtool: Make 'sec-address' always on

From: Christophe Leroy
Date: Sat Jun 24 2023 - 04:34:49 EST




Le 24/06/2023 à 09:33, kernel test robot a écrit :
> Hi Christophe,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on linus/master]
> [also build test WARNING on v6.4-rc7 next-20230623]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Christophe-Leroy/objtool-Make-sec-address-always-on/20230621-232305
> base: linus/master
> patch link: https://lore.kernel.org/r/e7e1de1d01194df3ff4053cb0815fc2ddba33213.1687360711.git.christophe.leroy%40csgroup.eu
> patch subject: [PATCH] objtool: Make 'sec-address' always on
> config: x86_64-randconfig-c002-20230622 (https://download.01.org/0day-ci/archive/20230624/202306241520.4jIgEhK4-lkp@xxxxxxxxx/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> reproduce: (https://download.01.org/0day-ci/archive/20230624/202306241520.4jIgEhK4-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202306241520.4jIgEhK4-lkp@xxxxxxxxx/
>
> All warnings (new ones prefixed by >>):
>
>>> vmlinux.o: warning: objtool: ibt_selftest+0x14 (.text+0x92b54): sibling call from callable instruction with modified stack frame
> vmlinux.o: warning: objtool: .altinstr_replacement+0x19a4: redundant UACCESS disable
> vmlinux.o: warning: objtool: iovec_from_user.part.0+0xb1 (.text+0x1c47761): call to copy_iovec_from_user.part.0() with UACCESS enabled
> vmlinux.o: warning: objtool: ibt_selftest+0x1e (.text+0x92b5e): return with modified stack frame
>

I can't really see any link between that warning and the changes in the
patch.

Whatever, this patch will be discarded as pointed out by Josh.

Christophe

>
> objdump-func vmlinux.o ibt_selftest:
> 0000 0000000000092b40 <ibt_selftest>:
> 0000 92b40: f3 0f 1e fa endbr64
> 0004 92b44: e8 00 00 00 00 call 92b49 <ibt_selftest+0x9> 92b45: R_X86_64_PLT32 __fentry__-0x4
> 0009 92b49: 55 push %rbp
> 000a 92b4a: 48 89 e5 mov %rsp,%rbp
> 000d 92b4d: 48 8d 05 02 00 00 00 lea 0x2(%rip),%rax # 92b56 <ibt_selftest_ip>
> 0014 92b54: ff e0 jmp *%rax
> 0000 0000000000092b56 <ibt_selftest_ip>:
> 0000 92b56: 90 nop
> 0001 92b57: 48 85 c0 test %rax,%rax
> 0004 92b5a: 5d pop %rbp
> 0005 92b5b: 0f 94 c0 sete %al
> 0008 92b5e: e9 00 00 00 00 jmp 92b63 <ibt_selftest_ip+0xd> 92b5f: R_X86_64_PLT32 __x86_return_thunk-0x4
> 000d 92b63: 66 2e 0f 1f 84 00 00 00 00 00 cs nopw 0x0(%rax,%rax,1)
> 0017 92b6d: 0f 1f 00 nopl (%rax)
>